Game Development Reference
In-Depth Information
player needs a way of steering her avatar around the world, as in an action game.
Chapter 13, “Action Games,” includes a discussion of avatar movement in games
featuring first- and third-person perspectives.
Games featuring context-sensitive perspective commonly use one of two user inter-
faces:
point-and-click
or
direct control
.
POINT-AND-CLICK INTERFACES
In this user interface, the player clicks with a mouse cursor somewhere on the
screen. If the corresponding location in the game is accessible, the avatar walks to
it. If the player clicks an active object, the avatar walks to that object and picks it
up or manipulates it in an appropriate way. The section “Manipulating Objects”
later in this chapter discusses object management more extensively. The disadvan-
tage of a point-and-click UI is that the player can easily point to areas that aren't
accessible to the avatar (halfway up a cliff for example). Sometimes an area that
looks as if it should be perfectly accessible is actually inaccessible, which can be
frustrating for the player.
The point-and-click interface is an indirect control mechanism and was for many
years the de facto standard for adventure games. It makes the player feel as if the
avatar is a person separate from himself rather than a puppet whose every move-
ment is directly controlled, and this contributes to the depth of the character. First
the player clicks, then the avatar walks—if she can; if she can't, she will usually say
so aloud. It works well in traditional adventure games with no action challenges.
However, because traditional adventures are increasingly rare and action-adventure
hybrids have become more common, the point-and-click interface is gradually
being replaced by direct control interfaces.
DIRECT CONTROL INTERFACES
In a direct control user interface, the player steers the avatar around the game
world, rather like driving a car. On a console controller, the joystick or D-pad nor-
mally manages this; on a personal computer, the mouse or keyboard steers the
avatar as in an action game. This is now the standard for action-adventure games,
whether in third-person or context-sensitive camera models. A few more traditional
adventure games have started to adopt a direct-control interface also.
Grim Fandango
from LucasArts is one that uses a context-sensitive camera model, which is rather
unusual. See the sections “Screen-Oriented Steering” and “Avatar-Oriented
Steering” in Chapter 8, “User Interfaces.”
MOVEMENT SPEED
No matter what camera model or user interface you choose, you should implement
both walk and run movement modes so the player can move slowly through unfa-
miliar spaces and quickly through familiar ones. If the game requires the player to
move repeatedly through areas he already knows well, the player may find
